Infrared spectroscopy and the study of used lubricating oils is known in the art. Infrared spectroscopy involves the twisting, bending, rotating and vibrational motions of atoms in a molecule. Upon interaction with infrared radiation, portions of the incident radiation are absorbed at particular wavelengths. The multiplicity of vibrations occurring simultaneously produces a highly complex absorption spectrum characteristic of the molecules. See, e.g., Willard et al., Instrumental Methods of Analysis, 5th ed., Chap. 6, D. Van Nostrand Company (1974). In the past, infrared spectroscopy has been used to analyze lubricants for purposes of determining lubricant degradation, contamination, additive depletion and other use parameters or characteristics. Typically, a system operator would insert a sample of lubricant into a spectrometer which would provide a spectrum of the sample. A computer coupled to the spectrometer would process the spectrum data in order to determine one or more of the above parameters.
Unfortunately, these conventional systems suffered from various drawbacks. For example, each system was designed to analyze only a particular type of lubricant. Thus, it was necessary to know the type of lubricant which was to be analyzed prior to having the system perform the actual analysis. In the event a system designed to analyze one type of lubricant was accidentally used to analyze a different type of lubricant, the system could produce erroneous results. If a system designed to evaluate mineral lubricant was used to evaluate a synthetic lubricant, the system could produce output information which did not accurately analyze the use characteristics of the lubricant. This meant that a system operator had to be careful to ensure that a system designed to analyze a particular type of lubricant was not used to analyze an incompatible lubricant. It also meant that if the system operator did not know the type of lubricant to be analyzed, the system operator had to first find out such information before knowing whether a given system could provide an accurate analysis. This could result in delays and imposed additional responsibilities on the system operator, thereby increasing the costs associated with system operation.
Furthermore, because each system was limited in application to a particular type of lubricant, different and/or reconfigured systems were required for analyzing different types of lubricants. This could lead to higher system costs as a result of having to obtain and operate two or more systems each dedicated to a respective type of lubricant.
In view of the aforementioned shortcomings associated with conventional systems for analyzing lubricants, there is a strong need in the art for a system which does not require prior knowledge of the type of lubricant being evaluated in order to ensure accurate results. More particularly, there is a strong need in the art for a system which can identify automatically the type of lubricant being analyzed and can automatically analyze the lubricant based on the identified type. There is a strong need in the art for a system which does not require the system operator to know the particular type of lubricant, thereby reducing the potential for error in the analysis and reducing operating costs. In addition, there is a strong need for a system which is capable of detecting and analyzing several different types of lubricants automatically so as to obviate the need for several separate and/or reconfigured systems.
The present invention addresses each of the above-mentioned shortcomings found in conventional systems as will be appreciated based on the following description.